Telephone system



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POPE.

TELEPHONE SYSTEM.

Patgnted Mar. 6, 1894.

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TELEPHONE SYSTEM. v No. 515,940. I Patented Mar. 6, 1894.

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UNITED STATES ATENT FFlCE.

' EDWIN POPE, on ounnno, CANADA.

TELEPHONE SYS TEM.

SPEGIFICATION forming part of Letters Patent No. 515,940, dated March 6, 1894.

Application filed September 2, 1892. Serial No. 444.876. (N0 model.)

To all whom it may concern.-

Be it known that I, EDWIN POPE, a subject of the Queen of Great Britain, residing at Quebec, in the Province of Quebec, Canada, have invented certain new and useful Improvements in Telephonic Systems, of which the following is a full, clear, and exact de- I scription.

This invention relates to telephonic systems, and has special reference to the exchange apparatus and circuits. p

The object of the invention is to do away with the spring jacks and the large numbers of extensible terminals, used in connection with the magneto system.

This invention utilizes a portion of the invention described in my application filed August 3, 1892, Serial No. 442,011, and is designed as an improvement thereon.

The invention will now be described with reference to the accompanying drawings, in which- Figure 1 represents a diagrammatical view of a multiple switchboard showing the disposition of two subscribers circuits therein. Fig. 2 is a representation of an operators switching apparatus, used to test and to connect any two subscribers lines. Figs. 3 to 7, inclusive, show the circuits and connections which are successively made by an operator in connecting any two subscribers. Fig. 8 shows a form of plug which may be used with this system, and Fig. 9 shows a diagram of circuits for a ground return board, which is comprehended by my invention.

Referring to the drawings by letters and figures, G, D, E, F, G, H, I, J, represent the respective sections of a multiple metallic circuit switch board.

A and B respectively represent two subscribers stations, the wires a, b, and 0,61, from which, lead through open contact points on each of the sections and finally terminate at one of the sections where its call is received and connections made with any other subscriber. Only two subscribers circuits are shown, but theyall run in the same manner through the switchboard. As shown the circuit of subscriber A terminates at section H,

and the circuit of subscriber B terminates at section 0. The extreme ends of the wires of each subscribers circuit extend from the open contacts on the last section of board to the armature e, and back stop f, of an electromagnet K. The annunciator or drop magnet L is connected in each subscribers circuit at a point between the last and next to the last sections of the switchboard. The open contact points mentioned are simply sockets into which a plug may be inserted to establish electrical connection between the plug and the line; these open points are represented on the drawings by 0 p. In connection with each subscribers circuit a test wire 25 is provided. This wire will include magnet K and will be grounded at one end as shown at t and dead at the other. The testwire extends from ground through magnet K and thence through all the sections of the board. In each section it is provided with an open contact point to which connection may be made by plugging in. The construction of these open points is not a material feature of my invention, and may be of any approved design. I suggest that the sockets may be triangular holes formed in insulating material and having metallic contacts placed in each side or wall of the hole, two of which will connect respectively with the subscribers line wires and the other with the same subscribers test wire. A triangular plug shown in Fig. 8, having a metallic contact on each face may be used in connection with such a socket.

Fig. 2 represents a switching apparatus and mechanism connected therewith, several of which are at the control of each operator in charge of a section of the board. This switching apparatus is of the same form as that described in my application above referred to. It consists of a cylinder N of insulating material having placed in its surface four longitudinal rows of metallic contact pieces. A crank it and a notched wheel and spring a, are provided, by means of which the operator may impart a step by step rotary movement to the cylinder. Each movement of the cylinder carries it a distance equal to the distance between the rows of contact pieces. Upon the surface of the cylinder ten metallic springs bear; they are numbered consecutively from 1 to 10. The contact pieces are placed in various positions in the paths of the springs, so that the connections hereinafter described may be made when the cylinder is turned. For convenience, the cylinder contains two sets of the contacts illustrated in Fig. 2, one on each side. Springs Nos. 1 and 2 connect through a flexible cord, respectively, with two contact points on a plug 0'. This same plug has a third contact point which connects through a flexible wire 1" with battery r and thence to ground. Springs 2 and 3connect respectively through a flexible cord with two of the contacts of another plug 5. The third contact on said plug being connected by Wire 8 with spring 9. Springs at and 5 connect with the operators instruments. Springs 6 and 7 connect with the magneto generator. Spring 8 connects with the battery V, which is grounded on the other side, and spring 10 connects with the galvanometer or other indicator Y, which is also grounded on the other side.

The operation is as follows: It is understood that the subscribers circuits arenormally held closed by springs acting upon the armatures e in opposition to magnets K. Suppose subscriber A to call; his annunciator which is located at section H drops. Operator takes plug a" which is connected to one of the switching apparatuses N, and plugs into subscriber As circuit at the point 0, p. The plug is inserted in such a way that the battery r is connected to the test wire t and energizes K which opens the subscribers circuit and holds it in that condition until the plug is removed. The switch N is supposed to be in the position shown in Fig. 2, which is its first position. As soon as K opens the line, operators instruments are put into circuit with subscriber A as follows, see Fig. 3: from operators instruments by spring 4, through the switch to spring 2, plug 7', wire a, subscriber A, wire I), plug r, spring 1, through the switch to spring 5, and back to operators instruments. Operator gets the connection wanted and places plug .2 into subscriber Bs circuit, which represents the subscriber called for. If B is free, (the indication of which will appear hereinafter,) operator turns switch N to the second position, which puts magneto current to subscriber Bs line over the following circuit, see Fig. 5: from magneto to spring 6, through the switch to spring 3, to plug 8, wire 0, subscriber 13, wire d, plug 8, spring 2, through the switch to spring 7, and back. to magneto. Another circuit is also completed through the battery V as follows: from battery V to spring 8, through the switch to spring 9, to plug .9, test wire t, magnet K, and through ground to battery V. Contacts 8 and 9 in the second posi tion of the switch come under the springs a little before the others and K therefore opens subscriber Bs line before the magneto current is put on; consequently drop magnet L on Bs line will not be affected. Battery V remains on the test wire until plug sis removed. Operator then turns switch to the third position, which connects A and B together over the following circuit, see Fig. 6: from subscriber A, by wire a, annunciator, plug 7*, spring 2, plug .9, wire cl, subscriber B, wire 0, plug 8, spring 3, through the switch to spring 1, plug '1', wire I), to subscriber A. In this condition it will be seen that subscriber As drop magnet is in the circuit with the subscriber, while Bs drop magnet is out of the circuit. Consequently, when either of the subscribers rings off As drop will be affected, but Bs drop will not be affected. Hence it becomes the duty of the operator immediately after connecting the two subscribers together to restore the drop, so that it may be used as the ring off signal. These conditions are brought about, it will be seen by reason of the fact that the drop magnets are connected in the circuits between the last and next to the last sections of the board. When switch N is turned to the fourth position, the two subscribers are together with the operators instruments in circuit. This is utilized by the operator in case she wishes to know whether subscribers are talkin g properly.

Fig. 4 illustrates how the test is accomplished, it represents the two plugs r and s inserted as before described, and the switch N at its first position. If now subscriber B is busy when the plug 8 is inserted, bat tery V controlled by another operator will be 011 the test Wire, as indicated in dotted lines, and a circuit will be established through the galvanometerY or other indicator, which will notify the operator the moment she inserts plug 8, that subscriberB is busy.

\Vhen this invention is applied to ground circuit systems, the sockets and plugs will be double instead of triple, and the circuits will be as shown in Fig. 9, which is clear without description.

It will be observed that spring jacks and extensible terminals are eliminated from the board entirely, the face of the board containing nothing but sockets having fixed terminals, and the space behind the face of the board is given up entirely to the wires connecting the sockets. The annunciator is of the ordinary description.

Having thus described my invention, I claim- 1. In a multiple switchboard, a subscribers circuit extending to plugging in points on each section of the board and finally terminating at its own section, an electromagnetic circuit controller at the terminus of the circuit, a testcircuit including said electromagnetic circuit controller and an annunciator in the circuit between the last and next ICO to the last plugging in points, for the purpose sources of current respectively with the test set forth. wires of any two subscribers circuits. 1o

2. In a telephone exchange system, the Intestimony whereof Isubscribe my signacombination with the subscribers circuits of ture in presence of two witnesses.

5 separate local test wires normally without EDWIN POPE.

battery connections, respectively therefor, WVitnesses: two sources of current under control of an W. H. CUFF,

operator, and means for connecting said A. GASAULT. 

